The presence of hydrogen cyanide (HCN) in various gaseous streams complicates removal of additional impurities, e.g., removal of H.sub.2 S or CO.sub.2, and poses problems insofar as product quality and pollution control requirements are concerned. In particular, gas streams derived from the gasification of coal generally have significant minor quantities of HCN which must be dealt with before the gas is utilized.
Accordingly, a practical and efficient procedure for removing impurity HCN might have great economic importance. The invention is such a process.